Function fuzzy_suggestions 

pub(crate) fn fuzzy_suggestions(
    kind: &ObjectTypeCheckErrorKind,
    source: &str,
    primary_range: &Range<usize>,
    candidates: &Candidates,
) -> Vec<Suggestion>

LSP-side enrichment: for Catalog::Unknown{Item,Schema,Database,Cluster}, fuzzy-match the offending name against the corresponding pool and return one Suggestion containing the closest alternatives. Returns an empty vec for variants we don’t enrich (everything else, including UnknownColumn/UnknownFunction whose suggestions come from upstream).